The great California borax deposits are found at Searles Lake, in California's Death Valley. The deposits are found within the Mojave Desert in the eastern part of California on the Nevada border.
Searles Lake is famous for the long list of evaporate minerals that form in and around the lake. “Evaporate minerals” are minerals that are dissolved in water and crystallize as the water evaporates. The minerals found there include halite, hanksite, borax, tincalconite, thenardite, gypsum, ulexite, searlesite, and trona, to name only a few.
Borax was mined from Searles Lake by John W. Searles, the “Borax King,” beginning in 1873. He called his company the San Bernardino Borax Mining Company. Because the borax industry is so important in California’s history, the Searles Lake borax discovery is an official California Historical Landmark.